Keyboard Enthusiast's Guide - Hardware Edition

Introduction

Recently, I was captivated by Amazon's recommendations and ended up getting a Nuphy Air60. I even spent the entire weekend researching mechanical keyboards. While keyboards are ubiquitous devices, a deeper dive reveals that this niche is quite expansive, with many enthusiasts treating keyboards as collectibles.

How Keyboards Work

Mechanical keyboards can generally be broken down into several components: the casing, keycaps, switches, PCB, and layout. However, the most crucial part is the PCB, which determines whether the keyboard functions properly and provides input capabilities.

A keyboard is essentially a multitude of switches. When a key is pressed, the microcontroller detects which key has been activated and sends the corresponding signal to the computer. We'll go into more detail about this in tomorrow's firmware article.

Connection Methods

As mentioned earlier, a keyboard is made up of countless switches, but that's only half the story. Keyboards can be categorized into several types based on their connection methods:

Membrane Keyboards

Between the circuit board and keycaps, there is a three-layer membrane. The middle layer acts as an insulator, while the upper and lower layers correspond to the keyboard's positions. The upper layer is conductive, and when a key is pressed, it contacts the lower layer to complete the circuit. Common inexpensive keyboards are typically membrane keyboards.

Mechanical Keyboards

Mechanical keyboards operate primarily through the mechanical structure of the switches, with each switch being independent. When a key is pressed, the stem inside the switch compresses metal contacts, causing them to collide and complete the circuit. Depending on the design, different tactile feedback can be achieved.

Switch Types

The most common types include brown, red, blue, and black switches. However, a deeper exploration reveals that there are many more types of switches beyond these four, which can primarily be categorized into two groups: linear switches and tactile switches.

Casings

Casings can mainly be divided into plastic and metal. While there is not much functional difference, the casing affects the typing feel and aesthetic.

Most mass-produced keyboards on the market are primarily made of plastic, though some brands, like Keychron, also offer aluminum-cased keyboards. Plastic keyboards tend to be lighter, but their finish and tactile feel often lack the quality found in metal cases, which is why many custom keyboard enthusiasts prefer metal casings.

Keycaps

Keycaps can be distinguished by material, shape, and coloring methods.

Material

Common keycap materials include ABS and PBT.

ABS keycaps are usually cheaper to produce and softer, which can lead to them becoming shiny with prolonged use. PBT keycaps are somewhat more expensive and tend to be more brittle with a rougher surface compared to ABS.

However, even if a keycap is labeled as PBT, it might not be 100% made from that material.

For example, GMK keycaps are well-known for being made from ABS, yet they maintain exceptional quality, making them a popular choice among keyboard enthusiasts.

Coloring Techniques

Coloring methods can be categorized into laser, ink, dye-sublimation, and two-shot molding. Each method has its pros and cons, but the more premium keycaps typically use dye-sublimation or two-shot molding due to issues like fading that can occur with ink or laser methods.

Dye-sublimation involves heating ink and embedding it into the keycap material, allowing the ink to penetrate the plastic. This process minimizes wear on the printed characters, giving the appearance that the characters are embedded within the keycap.

Since dye-sublimation requires heating the ink, it is usually used on more heat-resistant PBT keycaps, while two-shot molding is more commonly found on ABS keycaps.

Two-shot molding involves forming the lettering portion from one type of resin and then molding another color over it. Since the lettering becomes part of the keycap, it won’t fade and can achieve vibrant, attractive color combinations. Although each character requires additional molding, bulk production can reduce costs.

Shape

Keycap shapes can primarily be divided into Cherry, MDA, OEM, and XDA. Cherry profile is probably the most common shape.

To those unfamiliar with custom keyboards, many keycaps might look similar at first glance, but each profile has its unique characteristics, including variations in height and shape across different rows.

PCB

The "circuit" part of the PCB will be discussed in tomorrow's firmware article. However, to enhance the typing experience, many custom keyboard enthusiasts now have specific requirements for PCBs, with common preferences including PCB thickness and whether they feature slots.

Slots on a PCB serve several purposes, commonly seen on either side of transformers to separate high and low voltage components, preventing short circuits.

In keyboard PCBs, slots are typically added to increase flexibility and softness. A slotted PCB can provide a softer feel during typing.

Additionally, modern mechanical keyboard PCBs often include hot-swappable functionality, allowing switches to be inserted into sockets soldered onto the PCB rather than being directly soldered in. This design makes it easy to swap out switches without desoldering.

Structure

Currently, the most common structures are the tray mount and the increasingly popular gasket mount. The tray mount is a familiar fixed structure where the PCB is secured to the casing with screws. Most mass-produced mechanical keyboards follow this design.

The gasket mount, on the other hand, secures the PCB without screws, using a positioning plate to clamped between the upper and lower layers of the casing. However, the positioning plate is surrounded by gaskets, providing a softer, more flexible typing feel.

Layout

Layouts are categorized primarily by the number of keys: 30%, 40%, 60%, 65%, 70%, 80%, and 100%; and by key placement, they can be divided into ANSI, ISO, and JIS. JIS is the layout used for Japanese keyboards, while most users in Taiwan primarily use ANSI.

Some PCBs are designed to be more flexible, such as supporting both ANSI and JIS layouts, allowing for split spacebars or split backspace configurations based on user preferences. Personally, I have grown accustomed to a split backspace, placing it above the Enter key.

Conclusion

The world of custom keyboards is quite vast, with many enthusiasts on a quest to find their ideal keyboard, often unaware of how many options exist. However, this also means that if you're patient, you might find a great deal on a gently used keyboard that someone else barely used.

The custom keyboard market is quite saturated, as many can produce PCBs. Therefore, the competition now often lies in design aesthetics, craftsmanship, color variety, and customizable options. If you've explored the world of custom keyboards, you may have noticed a significant presence from manufacturers in China.

Due to the "custom" nature of these keyboards, they are difficult to mass-produce and often require group purchases to obtain. Additionally, due to factory timelines, waiting periods can stretch to three or four months.

However, if you're interested in keyboards, it might be worth exploring if there's a custom keyboard that meets your needs. Personally, I believe the quality and appearance are truly unmatched by mass-produced keyboards. At least, it's much cheaper than buying a car.